A certain article reported the following observations, listed in increasing order, on drill lifetime (number of holes that a drill machines before it breaks) when holes were drilled in a certain brass alloy. 11 14 20 23 30 37 39 43 48 50
60 62 64 66 69 71 75 77 78 79
81 83 85 90 92 94 95 98 100 103
104 104 112 117 123 135 139 140 149 159
162 167 185 205 248 263 288 322 388 513
Compute the 25% trimmed mean for the lifetime data. (Round 25% trimmed mean to four decimal places.)

25% trimmed mean :